Flash Gordon in the Caverns of Mongo, by Alex Raymond (HC, 1936, $7, which is 1/3 the internet price.)
Hang on to your horses! This is the real thing! Flash Gordon, his "sweetheart" Dale Arden, and his scientist friend, Doctor Hans Zarkov have gotten themselves marooned on the planet of Mongo. Now that they are friends of the king of Vultan life has become bearable, except, that is, for Dale who just wants to get back to earth where she and Flash can be married. (I guess a marriage on Mongo won't do it.)
Our story begins as Zarkov is showing Flash his latest discovery- evidence that "within the core of Mongo there are, not one, but perhaps a dozen masses, possibly of rock, possibly of metal, possibly of some unknown substance, which are swinging back and forth in mighty arcs like medieval battering rams in their cradles! Unconsciously Flash Gordon's muscles had tensed. Now he stood erect, his head thrown back, his eyes burning deep into Zarkov's own... Zarkov stooped low over the crystal globe... Without doubt there is a sinister, intelligent force imprisoned within the very rocks of Mondo, seeking to batter its way to the surface!"
Soon we have our fearless threesome fighting Cavernmen, then the Vultans fighting the Cavernmen, then Flash fighting octopus-monsters on Titan (Jupiter's moon), then the octopus-things fighting the Cavernmen... As you see, it all gets a bit confusing, but oh, what fun! Look for this in the science fiction section, avail. 3/23.
